Some turbine blades for use in gas turbines employ load-bearing airfoil sidewalls, in which a cumulative centrifugal loading of the blade is carried radially inwardly via the airfoil sidewalls. In such a design, the thicknesses of radially outermost portions of the airfoil sidewalls determine the thicknesses of radially innermost portions of the airfoil sidewalls near a root of the blade. As turbine blades become larger and the rotational speeds of the blades become greater, the thicknesses of the radially innermost portions of the airfoil sidewalls become so great as to render such blade designs infeasible.